BS EN IEC 61158-5-26:2023
Industrial communication networks. Fieldbus specifications Application layer service definition. Type 26 elements (British Standard)

Standard No.

BS EN IEC 61158-5-26:2023

Published By

American National Standards Institute （ANSI)

Latest

BS EN IEC 61158-5-26:2023

Scope

The fieldbus application layer (FAL) provides user programs with a means to access the Fieldbus communication environment. In this respect, the FAL can be viewed as a "window between corresponding application programs." This part of IEC 61158 provides common elements for basic time-critical and non-time-critical messaging communications between application programs in an automation environment and material specific to Type 26 fieldbus. The term "time-critical" is used to represent the presence of a time-window, within which one or more specified actions are required to be completed with some defined level of certainty. Failure to complete specified actions within the time window risks failure of the applications requesting the actions, with attendant risk to equipment, plant and possibly human life. This document defines in an abstract way the externally visible service provided by the Type26 fieldbus application layer in terms of: • an abstract model for defining application resources (objects) capable of being manipulated by users via the use of the FAL service; • the primitive actions and events of the service; • the parameters associated with each primitive action and event, and the form which they take; and • the interrelationship between these actions and events, and their valid sequences. The purpose of this document is to define the services provided to: • the FAL user at the boundary between the user and the Application Layer of the Fieldbus Reference Model, and • Systems Management at the boundary between the Application Layer and Systems Management of the Fieldbus Reference Model. This document specifies the structure and services of the Type 26 fieldbus application layer, in conformance with the OSI Basic Reference Model (see ISO/IEC 7498-1) and the OSI Application Layer Structure (see ISO/IEC 9545). application processes. The FAL AE is composed of a set of object-oriented Application Service Elements (ASEs) and a Layer Management Entity (LME) that manages the AE. The ASEs provide communication services that operate on a set of related application process object (APO) classes. One of the FAL ASEs is a management ASE that provides a common set of services for the management of the instances of FAL classes. Although these services specify, from the perspective of applications, how request and responses are issued and delivered, they do not include a specification of what the requesting and responding applications are to do with them. That is, the behavioral aspects of the applications are not specified; only a definition of what requests and responses they can send/receive is specified. This permits greater flexibility to the FAL users in standardizing such object behavior. In addition to these services, some supporting services are also defined in this document to provide access to the FAL to control certain aspects of its operation. The principal objective of this document is to specify the characteristics of conceptual application layer services suitable for time-critical communications, and thus supplement the critical communications. A secondary objective is to provide migration paths from previously existing industrial communications protocols. It is this latter objective which gives rise to the diversity of services standardized as the various Types of IEC 61158, and the corresponding protocols standardized in subparts of IEC 61158-6. This document can be used as the basis for formal Application Programming-Interfaces. Nevertheless, it is not a formal programming interface, and any such interface will need to address implementation issues not covered by this specification, including a) the sizes and octet ordering of various multi-octet service parameters, and b) the correlation of paired request and confirm, or indication and response, primitives. This document does not specify individual implementations or products, nor does it constrain the implementations of application layer entities within industrial automation systems. There is no conformance of equipment to this application layer service definition standard. Instead, conformance is achieved through implementation of conforming application layer protocols that fulfill the Type 26 application layer services as defined in this document.

BS EN IEC 61158-5-26:2023 Referenced Document

• IEC 61131-3 Programmable controllers - Part 3: Programming languages*， 2013-02-01 Update
• IEC 61158-1:2023 Industrial communication networks - Fieldbus specifications - Part 1: Overview and guidance for the IEC 61158 and IEC 61784 series*， 2023-03-16 Update
• IEC 61158-6-26:2023 Industrial communication networks - Fieldbus specifications - Part 6-26: Application layer protocol specification - Type 26 elements*， 2023-03-28 Update
• IEC 61784-2-21:2023 Industrial networks - Profiles - Part 2-21: Additional real-time fieldbus profiles based on ISO/IEC/IEEE 8802-3 - CPF 21*， 2023-05-05 Update
• ISO/IEC 10731 Information technology - Open Systems Interconnection - Basic Reference Model - Conventions for the definition of OSI services*， 1994-12-01 Update
• ISO/IEC 60559 ISO/IEC/IEEE International Standard - Floating-point arithmetic*， 2020-05-08 Update
• ISO/IEC 646 Information technology; ISO 7-bit coded character set for information interchange*， 1991-12-01 Update
• ISO/IEC 7498-1 Information technology — Open Systems Interconnection — Basic Reference Model: The Basic Model*， 1994-11-15 Update
• ISO/IEC 8822 Amendment 2 - Information technology -- Open Systems Interconnection -- Presentation service definition - Nested connections functional unit*， 1998-12-20 Update
• ISO/IEC 8824-1 Information technology -- Abstract Syntax Notation One (ASN.1)-- Part 1:Specification of basic notation*， 2021-06-30 Update
• ISO/IEC 9545 Information technology - Open Systems Interconnection - Application layer structure*， 1994-08-01 Update
• ISO/IEC/IEEE 8802-3 Amendment 9 - Telecommunications and exchange between information technology systems - Requirements for local and metropolitan area networks - Part 3: Standard for Ethernet - Physical layer specificat*， 2021-12-15 Update

BS EN IEC 61158-5-26:2023 history

• 1970 BS EN IEC 61158-5-26:2023 Industrial communication networks. Fieldbus specifications Application layer service definition. Type 26 elements (British Standard)
• 2019 BS EN IEC 61158-5-26:2019 Industrial communication networks. Fieldbus specifications-Application layer service definition. Type 26 elements